Re: [PATCH V3] x86, UV: BAU performance and error recovery

[Greg KH <gregkh@suse.de>]

On Fri, May 28, 2010 at 02:43:35PM -0500, Cliff Wickman wrote:
> 
> On Fri, May 28, 2010 at 09:47:25AM -0700, Greg KH wrote:
> > On Fri, May 28, 2010 at 09:30:25AM -0700, H. Peter Anvin wrote:
> > > On 05/28/2010 06:33 AM, Cliff Wickman wrote:
> > > > - adds modification of tuning variables through /proc/sgi_uv
> > > 
> > > Adding new directories in /proc for a proprietary architecture is
> > > frowned upon, to put it mildly.  At the very least try to find a place
> > > in sysfs for it.
> > > 
> > > [Cc: gregkh in order to find a place in sysfs]
> > 
> > Hm, what type of files are you needing here?  Do they corrispond with
> > any specific hardware devices?  If so, just put them on the hardware
> > devices in sysfs.
> > 
> > thanks,
> > 
> > greg k-h
> 
> There is an SGI-specific directory in sysfs: /sys/firmware/sgi_uv
> though the tuning variables for the handling of the hardware Broadcast
> Assist Unit don't fit there very logically.  
> 
> The BAU's statistics are already displayed through the UV-only
> /proc/sgi_uv/ptc_statistics.  This was deemed necessary because of the
> potentially very large size of that file --- it is still true that a /sys file
> is limited to one page, is it not?

It is limited to one single value, which would never be larger than a
page, so yes, it is limited to one page.

What kind of information are you showing here?  Should this thing just
be in debugfs instead?  You can do whatever you want there.

thanks,

greg k-h